With the coming of senior and low fertility society, the labor population is greatly reduced, which further negatively affects the progress of the entire nation and society. To address this problem, robots gradually enter human daily life from the plants to assist human in dealing with hazardous work or trifles. As the robots frequently come into human life, it is quite important to develop a high reactivity, high load and safety manipulator. In the manipulator, mainly a mechanical joint is used to link two arms, so that the two arms pivot relative to each other to achieve the effect of moving the manipulator.
Generally speaking, to achieve the high reactivity and high load mechanical joint at the same time, a high strength structure and a high power motor must be used. Accordingly, the high reactivity and high load mechanical joint has a relatively large inertia when moving, so when the safety mechanism is actuated, a more powerful energy absorption device is required to stop the mechanical joint running at high speed. At present, the industrial manipulator may achieve the above objectives, but is heavy and has a high cost, so the manipulator cannot be realized in the service-type robots.
To improve the reactivity, load ability, and safety, nearly all the manipulators available on the market use the high power motor on the mechanical joint together with the expensive harmonic drive or different forms of safety devices to enhance the performance, so the manufacturing cost of the manipulators are quite expensive, thus limiting the robots from entering the daily life. If the conventional mechanical joint is used in consideration of the costs, the reactivity is low and cannot provide high load at high running speed. Meanwhile, the conventional mechanical joint is influenced by the backlash caused by the clearance between gears, the operation precision of the manipulator is reduced. Further, the reactivity of the manipulator using the conventional mechanical joint is slow, so in consideration of safety, if an additional protection device is provided, the cost of the conventional mechanical joint is increased, and it is not beneficial to the application of the robots in daily life.